Boat stabilizer



A ril 14, 1970 H. GORMAN 3,505,968

BOAT STABILIZER Filed June 19, 1968 54 INVENTOR HENRY GOBMAN Ar M 'uflw FIG 4 50 UM ATTORNEYS United States Patent U.S. Cl. 114-126 1 Claim ABSTRACT OF THE DISCLOSURE A boat stabilizer comprising a hydrofoil mounted for rotation below the hull of the boat on a substantially horizontal axis in alignment with and spaced below the longitudinal centerline of the boat. The hydrofoil is mounted with its leading edge disposed toward the front or bow of the boat and is rotatable about its axis to a first position wherein the convex surface of the hydrofoil is vertically disposed toward starboard, to a second position'wherein the convex surface of the hydrofoil is vertically disposed toward port, and toa third position wherein the convex surface of the hydrofoil is horizontally and upwardly disposed.

BACKGROUND OF THE INVENTION In boats, and particularly sailboats, a common problem is to counteract heel or roll about the boats longitudinal axis, which heeling or rolling is traditionally caused by the strength of the wind in combination with the direction in which the boat is heading. Also, of course, the intensity of the waves contributes to heeling or rolling of the boat. In any event, such heeling and rolling not only contributes to passengerdiscomfort, but also greatly reduces the speed and efliciency of the boat.

Attempts have been made to overcome the problem of heeling or rolling by the use of ballast, but this, of course, causes the boat to sit lower in the water, thus increasing water resistance by increasing the hulls Wetted surface. Other prior art approaches have been to provide two or more hulls; or, if a single hull is used, by using some form of outriggers. These arrangements are cumbersome and add to the expense of the boat, as does a complicated system of a plurality of hydrofoils, which has sometimes been used to overcome the aforesaid problems.

SUMMARY OF THE INVENTION The present invention relates to stabilizing means for a boat, particularly a sailboat, comprising the use of a single hydrofoil, movable between a plurality of positions to counteract rolling of the boat to starboard and to port, and when rotated to another position, to create lifting of the boat when the boat is running before the wind. The single hydrofoil is mounted on a substantially horizontal axis or shaft that is spaced below the longitudinal centerline of the boat while at the same time being in general alignment therewith. The hydrofoil is mounted on said axis so that the leading edge of the hydrofoil is disposed toward the front or bow of the boat. Means are provided for imparting rotation to the axis or shaft whereby the hydrofoil may be rotated to its desired position. More specifically, the hydrofoil may be rotated so that its convex surface is vertically disposed toward starboard, so that its convex surface is vertically disposed toward port, or so that its convex surface is horizontally and upwardly disposed. The latter position of the hydrofoil provides a lifting action on the boat and is used when the boat is running before the wind. The other two vertical positions are used when it is desired to effect either starboard or port tacking of the boat.

Accordingly, it is a primary object of the instant invention to provide simplified means for preventing rolling or heeling of a boat, particularly a sailboat, so that the boat 3,505,968 Patented Apr. 14, 1970 "ice will be maintained in an upright position whereby greater speed may be accomplished.

Another object of the instant invention is to provide stabilizing means of the character described embodying a single hydrofoil.

A further object is the provision of stabilizing means of the character described wherein a single hydrofoil may be quickly and easily moved to a plurality of different operative positions, depending upon the stabilizing action desired.

Another object of my invention is the provision of stabilizing means that may be easily applied to a boat, that are simple and inexpensive to manufacture, that are easy to operate, but which nevertheless are durable and efiicient in use.

Other objects, features and advantages of the invention will become apparent as the description thereof proceeds when .considered in connection with the accompanying illustrative drawings.

DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the best mode presently contemplated for carrying out the instant invention:

FIG. 1 is a side elevational View of a sailboat embodying the instant invention;

FIG. 2 is an elevational view of a slightly modified form of the instant invention;

FIG. 3 is a perspective view illustrating the position of the hydrofoil in starboard tack;

FIG. 4 is a front view of the boat with the hydrofoil in the position illustrated in FIG. 3;

FIG. 5 is a perspective view of the hydrofoil positioned in port tack;

FIG. 6 is a front view of the boat with the hydrofoil in the position illustrated in FIG. 5; and

FIG. 7 is a perspective view showing the hydrofoil in position to create a lifting effect when the boat is running before the wind.

DESCRIPTION OF THE INVENTION Referring now to the drawing, FIG. 1 shows a conventional sailboat 10 having a hull 12. Depending from the bottom surface of the hull is a keel 14, it being understood that the keel extends downwardly from the longitudinal centerline of bull 12, as is conventional. A pair of struts 16, 18 extend downwardly from keel 14, as shown most clearly in FIG. 1; and said struts rotatably receive an axis or shaft 20 therebetween. Fixedly mounted on shaft 20 for rotation therewith is a hydrofoil 22 having a flat surface 24 and a convex surface 26, as is conventional. The foil 22 further has a leading edge 28 and a rear edge 30, all in a manner well known in the art. It will be understood that reference to the term hydrofoil or foil as used herein refers to a member of wing-like configuration, as just described, and as illustrated in the drawings.

It will be noted that axis or shaft 20 is substantially horizontally disposed and is spaced below the lower edge of keel 14 and hence below the bottom surface of hull 12. Axis 20 is generally parallel to the centerline of hull 12 and is in substantial alignment therewith, whereupon when foil 22 is vertically disposed, as shown in FIGS. 1 through 6, the foil is in generally the same plane as that of keel 14.

The shaft 20 extends beyond one of its supporting struts and is provided at its extremity with a beveled gear 32 which cooperates with gear 34 to impart rotation to axis 20 and hence to foil 22. Gear 34 is carried by a vertically extending shaft 36 which extends upwardly above hull 12 and is provided at its upper extremity with an operating handle 38. It will thus be seen by operating handle 38, the foil 22 can be turned to the vertical position illustrated in FIGS. 3 and 4 wherein the dynamic effect will be to achieve starboard tacking of the boat. More specifically, with the foil positioned as illustrated in FIGS. 3 and 4, the resulting dynamic moment applied to the boat will be that illustrated by the arrows shown in FIG. 4. Conversely, when foil 22 is rotated to the vertical position illustrated in FIGS. 5 and 6, the resultant dynamic force will result in port tacking of the boat, as illustrated by the arrows in FIG. 6.

When the boat is running before the wind and it is desired to effect a lifting action on the hull, the foil 22 is rotated to a horizontal position with the convex surface of the foil upwardly disposed, as illustrated in FIG. 7.

With the foil in this position, the resultant dynamic forces 1 will obviously apply a lifting action to the hull of the boat as the boat runs before the wind.

It is not essential that the struts 16 and 18 which support shaft 20 extend downwardly from keel 14, but rather the keel could be eliminated entirely, if desired, whereupon the struts would extend downwardly from hull 12, as illustrated in FIG. 2.

Other means for imparting rotation to shaft 20 and hence foil 22 could be used, but the gearing arrangement illustrated has been found effective, not only because of its simplicity, but also because such an arrangement serves to maintain the foil in its desired position of adjustment. In other words, the resistance of the gears is sufficient to maintain the foil in position until handle 38 is turned by an operator to move the foil to another desired position of adjustment. Of course, any other suitablemechanical means could be utilized for releasably locking the foil in its desired position of adjustment.

As hereinbefore stated, the foil 20 is of conventional wing-like configuration. The size of the foil is not critical except to the extent that where more sail space exists on a boat, a larger foil should be used for effective results. The foil may be constructed of any desired structural material.

Also, it will be understood that the foil could be rotated to an intermediate position (not shown) wherein a lifting action and port or starboard tacking can be simultaneously accomplished.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described.

What is claimed is:

1. Stabilizing means for a boat having a hull, said means comprising a substantially rectangular hydrofoil consisting of a gently rounded leading edge, a pointed rear edge, a convex first surface and a substantially flat opposite surface, means for mounting said hydrofoil on a substantially horizontal axis generally parallel to the longitudinal centerline of said hull, said axis being spaced below the 'bottom of said hull in substantial alignment with said centerline, said hydrofoil being pivotally mounted on said axis with the leading edge of the hydrofoil disposed toward the bow of said hull, said mounting means comprising a pair of downwardly extending struts having a substantially straight shaft rotatably mounted between and supported by said struts, said hydrofoil being mounted on said shaft for rotation therewith, and means for imparting rotation to said shaft.

References Cited UNITED STATES PATENTS 713,830 11/1902 York 114137 3,324,815 6/1967 Morales 11439 FOREIGN PATENTS 38,812 1/1924- Norway.

TRYGVE M. BLIX, Primary Examiner U.S. Cl. X.R. 11439 

